Automatic train control



Aug. 11, 1925-. v

. J. l., DAWSONA AUTOMATIC TRAIN CONTROL Filed April 6, 1923 5 Sheecgfsheet 2 Magia,

Fatcnted Aug. ll, i925.

narran erratas isaasia JOSEPH L. DASON, OF FAR-MER CTY, ILLINOIS, ASSIGNOR O'F ONE-HALF T0 CARL F. NICHOLS, OF FARTJIEB OTY, ILLINOIS.

AUTOMATIC TRAIN CONTROL.

application mea april s, i923.

T0 all who/m. it may concern.'

Be it known that I, Josnrri L. DAwsoN, a citizen of the United States of America, residing at Farmer City, in the county of De Witt and State of illinois, have invented new and useful improvements in Automatic Train Controls, of which the following is a specification.

The purpose of the invention is to provide a mechanism comprising roadside and train-carried elements of which the former serves as the ordinary visual signal and the latter as an automatic stop in the event of disregard, by the engineer, of a signal set against him. T he invention further contemplates the provision of a device which is simple in construction and which is not subject to disarrangement as are mechanisms carried between the track and operated by devices carried underneath the train, nor is it subject to the disarrangenient not infrequently attendant on electrically operated devices. Further the invention contemplates a. construction in which the carefulness of the engineer may be checked up, since the operation of the device is attended with the rupture of a readily frangible element of which the engineer is provided with a specified quantity and may be called upon to account for all of those which are damaged in a run, which will indicate the number of' times he has disregarded a signal set against him.

l/Vith these general objects in view the inzvention consists in a construction and coinbination of parts of which a preferred embodiment is shown in the accompanying` drawings, wherein Figure 1 is a view in side elevation showing the application of the invention.

Figure 2 is a front elevational view of the structure of Figure 1, the inoperative position of the signal being indicated in dotted lines.

Figure 3 is a central vertical sectional view of the ground-carried element.

Figure 4 is a transverse sectional view of the structureof Figure 3 on' the plane of the axis of the pivotal shaft of the signal arm, as indicated by the line 4 4 of said ligure.

Serial No. 630,336.

Figure 5 is a plan view, with the cover removed, of the train-carried element.

Figure G is a horizontal sectional view on the plane indicated by the line (5;6 of 55 Figure 5.

Figure 7 is a detail perspective view of the. terminal section of the signal arm which is provided with the cushion.

Figure 8 is a detail perspective view illusa 60 trating one of the replaceable frangible elements.

ln order to carry out the purposes of the invention, it is necessary to provide a roadside-carried element A and a train-carried through a hinge carried door 11 equipped 70 with a suitable lock. The housing 10 encloses the operating motor 12 designed for remote control from the signal tower. Surmounting the housing 10 there is a supplemental housing 13 in communication with 75 the main housing 10 through the top of the latter and through the bottom of the supplernental housing. A shaft 14 is journalled in the opposite walls of the supplemental housing and at one end protrudes laterally 30 therefrom for the reception of the sector 15, provided as is usual in signal devices, with the differently colored glasses 16 through which the light of the lantern 17 may be observed in the different positions of the sector to indicate a clear track or danger. rlhe shaft 14, being' a rock shaft, its movement results in angular movement imparted to the sector to dispose any one of the glasses 16 in front of the light from the 90 lantern 17.

Angular movement is vimparted to the roclr shaft 14 by means of an arm- 18 care ried by the latter and operatively connect-y ed with the motor by means generally indicated at 19, the arm 18 being limited to a substantially horizontal position by a transverse rod 20 spanning the opposite walls of the supplemental housing 13 in parallelism with the shaft 14. lNhen the arin 18 is in 100` abutting relation with said rod, the sector i5 is iii the position exposing the danger `of appropriate screws `or other glass to the light of the lantern 17. The sector l5 is keyed or otherwise secured to the shaft 14 to preclude angular movement with respect to the shaft, so that there may be a positive connection between it and the shaft which will prevent any disarrangement of the parts.

The protruding extremity of the shaft also carries the signal arm 2l secured to the shaft in such a way that relative angular movement between the two is precluded. Thus when the sector is in the position indicating danger, the signal arm will be disposed in a horizontal position and projecting inward toward the track, the dimensions of the main casing and the attendant part-s being such that the arm will, in its horizontal position, dispose it approximately the level of a header beam of an engine on which the train-carried element B is supported.

The signal arm 21, in its horizontal position, being designed for impact by a member of the train-carried element by means r of which the air-brake mechanism is operated, is composed of two sections 2l and 2lb of which the latter is held normally in the plane of the former but is capable of swinging movement to either side of the same. APreferably the section 21b is pivotally attached to the section 21 by means of a hinge pintle 22 which is surrounded by a spiral spring 23 connected at its opposite extremities to the sections 21v and 2l", the spring being designed to hold the sections normally inthe same plane but permitting the section 2lb to be swung yieldably to either side. In order that the impact from the train-carried element may be cushioned as much as possible, the extremity of the section 21b is equipped with a cushion 2lc to prevent damage to the section 2lb when the device is called upon to actuate the train-carried element B.

It is apparent from the description just preceding that the signal arm and sector are operable :from the signal tower by the attendant therein and when the signal arm is set in the danger position in which itis horizontally disposed, the sector is disposed to place the red glass in front of the light from the .lantern 17. Iii' the engineer is attentive to his business the device serves as a signal and he will bring his train to a stop. If he disregards the signal, the extremity of the signal arm is in the position to intercept the member of the train-carried element B and thus effect operation of the air-brake syste1n.`

The train carried element B comprises a housing 24 provided with a removable cover 24a secured in place on the housing by means acceptable fastening means. The housing is carried preferably on the header beam or pilot beamof the locomotive, although the design of the latter will dictate the position of the housing thereon as well as vdictate the position of the roadside-carried element A. It is only essential, to carry out the objects of the invention, for the disposition of the train-carried element be such that its actuating member will impact with the signal arm of the roadside-carried element. Y

The housing 24 encloses the air valve to which appropriate pipes are led from the airbralre mechanism, the valve being of any conventional form with the single modification that an actuating lever 26 be provided and formed with a slotted end 27 for engagement with a lateral pin 28 carried by the trip lever 29 which is mounted on a rock shaft 30 whose extremities are journaled respectively in the cover 24a and the opposite wall of the housing 24. The trip lever 29 has an eXteriorly exposed extremit f operating in a slot formed in the housing by cutting off a portion of the upper edge of the latter below the ledge as indicated at 3l, impact cushions 32 being secured to the inner walls of the housing at opposite ends of the slot to cushion thev trip lever in the remote positions of the latter. Obviously swinging movement of the trip lever from one end of the slot to the other will impart angular movement to the actuating lever 26 with the consequent operation of the air valve, and the resultant setting of the brakes. Such swinging or rocking movement is imparted to the trip lever by impact of its extremity with the signal arm 2l but such impact does not take place unless the engineer disregards a signal set against him. In order that the trip lever may be held in a neutral position where the air valve 25 will be held in inoperative position, a readily frangible element 33 is provided and consists of a preferably glass stick or tube inserted through oppositely disposed openings in the cover 242L and opposite wall of the housing 24, being held in position in said openings or perforations by pivotally mounted clip plates 34 adapted to be swung into positions unobstructing said openings when it is necessary to insert a new glass tube or stick to replace one thus broken. A. tension spring 35 is secured at one end to one end ot the wall of the housing 24 and at the other end to the valve leverg26 adjacent the end carrying the pin 28 and tends normally to move the lever in the direction operating the lever 26 to actuate the valve 25 but when the rangible element is in place, the spring is restrained.

In order that an attentive engineer may proceed with caution when a signal is set against him, the trip lever 29 is provided with a swinging extremity 29a` connected with the main portion of the lever preferably by a hinge 36 the leaves of which are..

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secured to the abutting ends` .of the extension 29@ and the body portion of the trip lever, so that the extension may move laterally in one direction with respect to the hook lever but is limited in movement in the other direction to a lposition in alignment with the main or body portion of the trip lever, in which aligned position it is yieldingly held by means of a spring 37. It may be swung laterally in the other direction by the engineer through the medium of a flexible connection 38 which is terminally connected to the eX- tension 29a and to one arm of a bell-crank lever 39 which is pivotally mounted on a suitable post 40 carried by the engine, the remaining arm of the bell-crank lever being connected with the extremity of a pull cord 41 passing through a tube 42 terminating in the engine cab, the pull cord being equipped with a terminal hand hole or finger ring or other suitable means by which it may be grasped. A spring 43 is connected with the bell-crank lever and tends normally to hold it in a position relieving strain on the ilexible element 38 so that the spring 37 may hold the extension in the position of alignment with the main or body portion of the trip lever.

In the event that the engineer disregards a signal set against him, the extension 29a will be in its normal position of alignment with the trip lever` 29 and will per force impact with the swinging extremity 2lb of the signal arm with the result that the frangible element 33 will be broken and the trip lever 29 swung rearwardly to rock the lever 26 and thus actuate the valve 25 and set the air brakes, the pull cord and the flexible member 33 having enough slack to permit this rearward swinging movement of the trip lever. ln the event that the engineer is giving proper attention, however, he may operate the pull cord 41 to rock the bell-crank lever 39 and thus swing the extension 292L to an angular position with reference to the body portion of the trip lever 29 so that the eX- tension will be above the point where it might impact with the signal arm.

lt is apparent that the device having once been actuated to set the brakes, it can be reset to neutral position by the insertion of a new frangible element 33 and, if the engineer is provided with a specified number of these on starting out on his run, a record may be kept of his carelessness through the number of replacements which he must make of the :trangible element.

Having described the invention, what is claimed as new and useful is:-

1. An apparatus for the purpose indicated comprising cooperating roadside and traincarried units ot which the latter embodies a housing, an air brake control valve carried in said housing, an actuating lever for said valve, said lever being provided with a slotted extremity, a trip lever pivotally mounted in said housing and having a pin engaging in the slot of the valve actuating lever, a replaceable 'trangible element supported by the casing and retaining the trip lever in neutra position, and an extension carried by the trip lever and movable relatively thereto to non-impacting relation with the roadsidecarried unit.

2. An apparatus for the purpose indicated comprising cooperating roadside and traincarried units oi which the latter embodies a housing, and an air brake control valve within the housing, a trip lever operativelyT connected with the air valve and disposed for impacting relation with the roadsidecarried unit, and a readily trangible element within the casing abutting the trip lever to maintain the same normally in neutral position.

3. An apparatus for the purpose indicated comprising cooperating roadside and traincarried units of which the latter embodies a housing, and an air brake control valve within the housing, a trip lever operatively connected with the air valve and disposed for impacting relation with the roadsidecarried unit, a readily frangible element within the casing abutting the trip lever to maintain the same normally in neutral position, the casing being provided with openings in opposite walls through which the frangible element may be inserted, and means carried by the casing and movable into and out of obstructing relation with said openings to maintain said frangible element in place and permit its replacement when broken.

4. An apparatus for the purpose stated comprising cooperating roadside and locomotive-located units, the latter unit including an air valve and an actuating lever eX- tending from the valve, a pivoted trip lever, operative connection between the actuating and trip levers, a replaceable readily frangible element engaged by the trip lever and retaining the same normally in neutral position, and means yieldably urging the actuating lever in a direction to hold the trip lever in such engagement with the said Jfrangible element.

5. An apparatus Jr'or the purpose stated comprising cooperating roadside and locomotive-located units, the latter unit including an air valve and an actuating lever extending from the valve, a pivoted trip lever, operative connection between the actuating and trip levers, a replaceable readily Jfrangible element engaged by the trip lever and retaining the same normally in neutral position, means yieldably urging the actuating lever in a direction to hold the trip lever in such engagement with the said rangible element, an extension hingedly mounted upon the trip lever whereby to be movable into and out of position for impact with the roadside unit, means normally holding the extension in active position, and manually operable means for moving the extension to inactive position.

6. Automatic train control mechanism comprising cooperating roadside and locomotive-located units, the latter unit including an air valve and an actuating leverextending from the valve, a trip lever operatively connected with the actuating lever and having an extension hingedly connected therewith, means yieldably holding the eX- tension in alinement with the trip lever, means connected With the actuating lever yieldably urging the same in a direction to open the air valve, a frangible element engaged by the trip lever and resisting movement of the same by the said urging means, the roadside unit comprising an abutment engageable by the extension of the trip lever when the extension is in alinement with the lever, and means connected With the extension of the trip lever and extending into the locomotive cab and manually operable to swing the extension to inactive position out of alinement With the triplever.

In testimony whereof I aix my signature.

JOSEPH L. DAWSON. 

